Circulating cooling installation for piston internal combustion engines

ABSTRACT

A circulating cooling system for piston internal combustion engines with a cooling jacket and control devices which interrupt the cooling circulation through the cooling jacket at least within the area of the combustion zones up to a first predetermined limit value of the temperature of the engine and/or of the time after the cold start of the engine, above the first predetermined limit value at first confine the circulation to a closed circulation which by-passes a radiator and avoids a fresh water exchange, and above a further predetermined temperature limit value include the radiator, a heat-exchanger and/or the fresh water exchange into the cooling medium circulation whereby the control devices include a cooling medium valve and/or a cooling medium pump adapted to be shut off as well as a three-way thermostat each with a separate control element each, of which the cooling medium valve and/or the cooling medium pump are actuated after reaching the first limit value and three-way thermostat after reaching the further temperature limit value; the control element of the cooling medium valve and/or of the cooling medium pump is thereby arranged at a location, at which the at least approximately maximum occurring cooling medium temperature becomes effective when the cooling medium stands still, whereas the control element of the three-way thermostat is disposed in the flow area of the closed circulation.

United States Patent [1 1 Henning et al.

[ 1 Apr. 15, 1975 1 CIRCULATING COOLING INSTALLATION FOR PISTON INTERNALCOMBUSTION ENGINES [75] Inventors: Richard Henning, Munich; ErwinSchweiger, Dachau, both of Germany [73] Assignee: Bayerische MotorenWerke Aktiengesellschaft, Munich, Germany 22 Filed: Mar. 22, 1974 21Appl. No.: 453,950

[30] Foreign Application Priority Data Mar. 22, 1973 Germany 2314301[52] US. Cl. l23/41.08; l23/4l.l; 236/345; 237/123 B [51] Int. Cl. FOlp7/14 [58] Field of Search 123/4l.01, 41.02, 41.08, 123/41.1, 41.29;237/123 B, 8 C; 236/345 [56] References Cited UNITED STATES PATENTS1,328,855 1/1920 Sweet 123/4108 1,767,598 6/1930 Mallory..... 236/3451,848,987 3/1932 Anibal 123/41,l 2,038,193 4/1936 Parsons 237/1232,086,440 7/1937 Rushmore. 123/41.08 2,445,684 7/1948 Mallory l23/41.082,468,735 5/1949 Brubaker 123/41.08 2,706,085 4/1955 Nallinger 237/82,749,049 6/1956 Smith 237/123 B 3,211,374 10/1965 Matulaitis. 237/123 B3,313,483 4/1967 Nallinger 236/345 3,851,629 12/1974 Mayr 123/4l.08

Primary ExaminerManuel A. Antonakas Assistant Examiner-Daniel J. OConnorAttorney, Agent, or FirmCraig & Antonelli [57] ABSTRACT A circulatingcooling system for piston internal combustion engines with a coolingjacket and control devices which interrupt the cooling circulationthrough the cooling jacket at least within the area of the combustionzones up to a first predetermined limit value of the temperature of theengine and/or of the time after the cold start of the engine, above thefirst predetermined limit value at first confine the circulation to aclosed circulation which by-passes a radiator and avoids a fresh waterexchange, and above a further predetermined temperature limit valueinclude the radiator, a heat-exchanger and/or the fresh water exchangeinto the cooling medium circulation whereby the control devices includea cooling medium valve and/or a cooling medium pump adapted to be shutoff as well as a three-way thermostat each with a separate controlelement each, of which the cooling medium valve and/or the coolingmedium pump are actuated after reaching the first limit value andthree-way thermostat after reaching the further temperature limit value;the control element of the cooling medium valve and/or of the coolingmedium pump is thereby arranged at a location, at which the at leastapproximately maximum occurring cooling medium temperature becomeseffective when the cooling medium stands still, whereas the controlelement of the threeway thermostat is disposed in the flow area of theclosed circulation.

15 Claims, 5 Drawing Figures PATENTED 1 1 5 3. 877, 443

sum 2 [1F 5 PMENTEBAPR 1 519. 5

SHEET 3 [IF 5 CIRCULATING COOLING INSTALLATION FOR PISTON INTERNALCOMBUSTION ENGINES The present invention relates to a circulatingcooling installation for piston internal combustion engines with acooling jacket and with control devices which interrupt the coolingcirculation through the cooling jacket at least within the area of thecombustion zones up to a first predetermined limit value of thetemperature of the engine and/or of the time after the cold-start of theengine, which above the first predetermined limit value at firstrestrict the circulation in a closed circulation in by-passing aradiator and in avoiding a fresh water exchange, and which above afurther predetermined temperature limit value incorporate the radiator,a heater heat-exchanger and/or the fresh water exchange into the coolingmedium circulation, whereby the control devices include a cooling mediumvalve and/or a cooling medium pump adapted to be shut off as well as aconventional three-way thermostat with a separate control element each,of which the cooling medium valve and/or the cooling medium pump areactuated after reaching the first limit value and the three-waythermostat after reaching the further temperature value.

The aim of the present invention resides in further improving such acirculation cooling system. To that end, the present invention residesin that the control element of the cooling medium valve and/or of thecooling medium pump is arranged at a location of the cooling jacketand/or of the cooling-medium line system at which, at leastapproximately the highest cooling medium tempetature occurring orstanding-still cooling medium becomes effective by heat conductionand/or thermal-siphon flow whereas the control element of the three-waythermostat is disposed within the flow area of the closed circulation.Up to the first predetermined limit value of the temperature of thecooling medium. exclusively that portion of the cooling medium can beincluded in this manner into the warm-up operation which is disposed inthe cooling jacket itself. As a result thereof, a rapid warm'up of theengine is favored with small structural expenditures.

These and further objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIGS. 1 and 2 are schematic views of a circulating cooling installationaccording to the present invention in the starting control phase and inthe end control phase, respectively, during the warm-up of an internalcombustion engine;

FIG. 3 is a side elevational view of a thermostat housing of acirculating cooling installation according to the present invention;

FIG. 4 is a longitudinal cross-sectional view taken aong line lV-IV ofFIG. 5; and

FIG. 5 is an end elevational view of the thermostat housing according toFIGS. 3 and 4.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, the circulatingcooling installation, schematically illustrated in FIGS. 1 and 2, of aninternal combustion engine 1 includes a conventional cooling jacket witha first area or region 2 which is arranged in the cylinder block of theinternal combustion engine and includes essentially the cylinder slidingsurfaces of the pistons of the internal combustion engine 1. The secondarea or region 3 of the cooling jacket is arranged in the cylinder headof the internal combustion engine 1. It includes, above all, thecombustion zones. The latter are essentially the combustion spaces andthe gas-exchange channels.

For the circulation of a cooling medium, the internal combustion engine1 includes at the usual places a cooling medium inlet opening oraperture 4 and a cooling medium discharge opening or aperture 5 whichare provided, respectively, at a geodetically low location in the firstarea 2 and at a geodetically high location in the second area 3 of thecooling jacket. A further geodetically high discharge opening oraperture 6 is formed in the second area 3 of the cooling jacket.Additionally, a further auxiliary discharge opening or aperture 7 may beprovided in the first area 2--possibly also at the location of thedischarge aperture 6.

A free, unobstructed cooling medium line 8 leads from the cooling mediumdischarge aperture 5 to a radiator 9 and terminates in the latter at ageodetically high place. The cooling medium line 8 passes a thermostathousing 11 at the height of a branching place 10. An expansion element12 ofa cooling medium valve 13 protrudes into the branching place 10,which is equipped with a disk valve 14. The plate 14 is operable toclose or open a control opening 15.

A radiator return line 16 leaves the radiator 9 at a geodetically lowplace, which connects the radiator 9 with the thermostat housing 11. Theradiator return line 16 is completely or partially closed off or openedup in the thermostat housing 11 within the area of a control opening 17by a disk valve 18. The disk valve 18, as also the disk valve 19, whichis provided for the opening or closing of the control opening 20 of a bypass 20', are component parts of a three-way thermostat 21 which isarranged in the interior space of the thermostat housing 11. Both diskvalves 18 and 19 are controlled by way of an expansion element 21' whichcarries out control movements corresponding to the temperature of theflow of the cooling medium through the control opening 17 out of theradiator 9 and through the control opening 20 out of the by-pass 20'.

A return line 23 branches off from a combining place 22 in thethermostat housing 11, which is in communication with the suction sideof a cooling medium pump 24. The cooling medium pump 24 supplies thecooling medium through a cooling medium line 25 by way of the coolingmedium inlet aperture 4 into the first area 2 of the internal combustionengine 1.

Furthermore, a discharge line 27 coming from a heater heat-exchanger 26terminates in the combining place 22; the discharge line 27 is again incommunication with an expansion tank 28 by way of a line 29.

Additionally, an auxiliary circulation line 30 terminates in thedischarge line 27; the auxiliary circulation line 30 is therebyconnected either to the discharge aperture 7indicated in dash lineor incase of omission of the discharge aperture 7, by way of an auxiliarycirculation line 30' to the place 31 between discharge aperture 6 andthe heater heat-exchanger 26 to the feedline 32 for the heat-exchanger26. A heater jacket 33 for a suction-line-throttle-valve 34 and atemperature value pickup or transmitter 35 of conventional constructionfor a fuel metering mechanism of the internal combustion engine 1 areinterconnected into this auxiliary circulation line 30. The feed line 32is connected to the discharge aperture 6. The flow cross section of thecooling medium within the area of the discharge aperture 6 is controlledby means of a valve 36 with a disk valve 37. The control thereby takesplace by way of an expansion element which projects into the second area3.

Both the heat-exchanger 26 as also the auxiliary circulation line 30 maybe connected directly to the discharge aperture 7 within the first area2 of the cooling jacket. In this case, the discharge aperture 6 may bedispensed with. It is only important that the location of the dischargeaperture 7 is so selected that a swirling or vortexing of the coolingmedium disposed within the second area 3 does not occur during thewarm-up operation of the internal combustion engine, and as a resultthereof an accelerated warm-up of the cooling medium in the combustionzones is assured during the cold start. The last-mentioned variation inthe solution is especially appropriate, when the internal combustionengine is started at extremely low ambient or outside tem peratures inorder to feed to the heater for the inside space of the vehicle coolingmedium heated up above the outside temperature as soon as possible.

In order that no air bubbles are enclosed during the filling up of thecirculating cooling system with the cooling medium, which would endangerthe troublefree operation of the cooling medium pump 24 as well as thecooling of the combustion zones, vent lines are provided according tothe present invention. For purposes of venting the radiator 9, a ventline 38 is connected thereto at a geodetically high location whichterminates uncontrolled in the thermostat housing 11 upstream of thecontrol opening 17. The termination place of this vent line 38 islocated in the geodetically high area of the thermostat housing 11.Adjacent to this termination place, a further vent line 39 branches offfrom the thermostat housing 11-also still upstream of the controlaperture l7-which is connected with the expansion tank 28. A stillfurther vent line 41 terminates within the area 40 of the further ventline 39; the still further vent line 41 thereby branches off from thecombining place 22 of the thermostat housing 11. The further vent line39 tapers within the area 40, i.e., is constricted within this area 40.The tapering or constriction place is thereby constructed as seat for afloat valve 42 which with an increasing cooling medium level closes offthe further vent lines 39 and 41 against the rising cooling medium. Theventing of the cooling system is ensured by the arrangement of thesevent lines. At the same time, a circulation of the cooling mediumthrough the vent lines, harmful for the rapid warm-up of the engine, isavoided by the float valve 42.

In the first control phase, according to FIG. 1, the disk valve 14 ofthe cooling medium valve 13 and the disk valve 18 of the three-waythermostat 21 close the control apertures 15 and 17, respectively, whenthe engine is cold and thus the cooling medium is cold. As a resultthereof. the cooling medium is cold. As a result thereof, the coolingmedium present within the area of the cooling medium line 8, of theradiator 9 and the return line 16 cannot flow to the cooling medium pump24. Since additionally, the discharge opening 6 is closed by the diskvalve 37, also no circulation of the cooling medium takes place evenwith a running cooling medium pump. As a result thereof, the coolingmedium present within the second area 3 of the cooling jacket of theengine 1 remains stationary, i.e., does not move so that a reduced heatremoval from the combustion zones exists in this area and simultaneouslya more rapid warm-up of the cooling medium present in this area takesplace. This action is therebeyond additionally favored in that thecooling mmedium present outside of the areas 2 and 3 of the coolingjacket does not partake in the warm-up operation of the engine. In thismanner, a very rapid warm-up of the walls of the combustion zones to anoperating temperature is attained in the illustrated position of thedisk valves 14 and 18 of FIG. 1, in which favorable combustionconditions will establish themselves in the combustion spaces both withrespect to the running porperties of the' engine as also with respect tosmaller proportions in harmful exhaust gas components. In particular,cold-start enrichments of the fuel-air mixture can be omitted after aparticularly short period of time.

During the warm-up operation of the engine, all disk valves except forthe disk valve 19 close the control openings coordinated thereto. Duringthis control phase, a circulation of the cooling medium therefore takesplace only if the discharge aperture 7 is provided within the first area2 of the engine 1 and the auxiliary circulation line 30 is connectedthereto or in case of' omission of the discharge aperture 6, the feedline 32 is connected by way of the auxiliary circulation line 30'. Thecooling medium supplied by the cooling medium pump 24 thereby flowsthrough the cooling medium line 25, enters by way of the cooling mediuminlet aperture 4 into the first area 2 of the internal combustion engine1, flows through this area-approximately along the flow paths indicatedin dash and dot lines-- branches off into two streams, reaches with afirst partial stream the auxiliary circulation line 30 through thedischarge aperture 7, flows through the heater jacket 33, flows byy wayof the temperature value pick-up or transmitter 35 into the dischargeline 27, and with a second partial stream the feed line 32 through theline 30' and flows through the heat-exchanger 26 also into the dischargeline 27. The recombined cooling medium stream flows again uncontrolledthrough the discharge line 27 into the combining place 22 of thethermostat housing 11 and then again reaches the cooling medium pump 24by way of the return line 23. In the course of this circulation, thecooling medium follows the path indicated by the arrows 43. In order toavoid in every case during the first control phase a cooling-off of thecooling medium by the heat-exchanger 26, it is appropriate under certaincircumstances not to permit the cooling medium to flow through theheat-exchanger 26 at the beginning of this control phase, for example,controlled by a time switch. Such a switch may be arranged at thelocation 44 and may be a conventional timer switch. The same purpose canalso be achieved by the arrangement of a valve corresponding to thevalve 36 at the location 44, whose control element is disposed in thecooling medium stream coming out of the discharge aperture 7 and flowingconstantly and uncontrolled through the auxiliarly circulation line 30and whose disk valve opens the auxiliary circulation line 30 to the feedline 32 only above a predetermined temperature of the cooling medium.

During this first control phaseapart from a thermosiphoning flowaswirling or vortexing of the cooling medium present in the second area 3is thus avoided.

Overheating appearances of the internal combustion engine are precludedalso under extreme loads during the warm-up operation in that the firstcontrol phase is timely terminated by response of the cooling mediumvalve 13.

By reference to FIG. 2, the second control phase will be describedduring the warm-up of the engine. The same reference numerals arethereby used for the individual parts of the cooling system as in FIG.I.

With an increase of the cooling medium temperature, the valve 36 opensthe discharge aperture 6. The prere quisites for a circulation of thecooling medium according to the arrows 45 are fulfilled thereby. Thecooling medium supplied by the cooling medium pump 24 thereby reachesthe first area 2 by way of the cooling medium inlet aperture 4, fromthere reaches the second area 3 in order to flow thereafter through thedischarge aperture 6 and through the feedline 32 into the heatexchanger26. Out of the heat-exchanger 26, the cool' ing medium reaches thecombining place 22 in the thermostat housing 11 by way of the dischargeline 27. From there, the cooling medium returns uncontrolled to thecooling medium pump 24 by way of the return line 23. Additionally, thereexists an auxiliary circulationassuming that in this embodiment thedischarge aperture 7 is not present and that the auxiliary circulationline 30' starts from the place 3l-whose flow path is designated by thearrows 46. The cooling medium thereby reaches the auxiliary circulationline 30' and 30 from the feed line 32, flows through the heater jacket33 and flows into the discharge line 27 by way of the temperature pickup35.

The control of the valve 36 takes place by way of an expansion elementwhich, at a predetermined temperature, so displaces the disk valve 37that the discharge aperture 6 is opened. At this control temperature,however, the expansion elements of the cooling medium valve 13 and ofthe three-way thermostat 21 do not as yet respond. The associated diskvalves remain in their positions closing the associated controlopenings. As a result thereof, neither a flow by way of the by-pass 20'through the control opening nor a flow through the radiator 9 takesplace in the second control phase.

In the course of the third control phase during the warm-up operation ofthe engine, the valve 36 is open and the cooling medium valve 13 opensthe control opening 15 as soon as the cooling medium reaches atemperature, at which the combustion zones within the area of thecooling jacket have a temperature sufficient for the operation of theengine without fuel enrichment and which is equal to or higher than thetemperature at which the valve 36 open, so that now also a circulationis possible by way of the by-pass according to arrows 47. The control ofthe cooling medium valve 13 takes place by way of the expansion element12 which is so arranged within the area of the geodetically high coolingmedium discharge aperture 5 that it is acted upon owing to thermo-siphonflow by the highest occuring temperature of the cooling medium in thesecond area 3, when the cooling medium is stationary or standing-still.

On the one hand, an excessive warm-up of the combustion zones and, onthe other, an excessive cooling off of the cooling medium is avoided bythe by-pass circulation 47, which would otherwise take place with aconduction of the cooling medium through the radiator 9. The remainingcirculations through the heat' exchanger 26 according to the arrows 45and through the heater jacket 33 according to arrows 46 remain preservedunchanged in this control phase. A part of the cooling medium leaves theengine I through the cooling medium discharge aperture 5 during thiscontrol phase, flows around the disk valve 14 and by way of the by-pass20', of the control opening 15 and of the open control opening 20reaches the combining place 22 in the thermostat housing 11, in which itjoins the flow path of the remaining circulations according to thearrows 45 and 46.

The warm-up operation of the engine terminates with the fourth controlphase. The cooling medium thereby reaches a temperature, at which alsothe disk valve 18 controlling the flow of the cooling medium through theradiator 9, which again is controlled by an expansion element, opens upthe control opening 17. With the beginning of the opening of the controlaperture 17, the disk valve 19 increasingly closes the control aperture20. As a result of the adjustment of the disk valve 19, the by-pass 20'is increasingly closed so that in addition to the described circulationaccording to the arrows 45 and to the auxiliary circulation according tothe arrows 46, the radiator-circulation according to the arrows 48 isadded. The cooling medium quantity forming the radiator-circulationreaches the radiator 9 uncontrolled out of the cooling medium dischargeaperture 5 through the cooling medium line 8. The cooling medium givesoff heat in the radiator 9 and reaches thereafter the thermostat housing11 by way of the return line 16. The cooling medium circumcirculatesthereat the disk valve 18 and mixes in the combining place 22 with thecirculation described hereinabove and designated by arrows 45, andto theextent that it is not yet completely interrupted-with the by-passcirculation 47.

A geodetic drop is provided for venting purposes, contrary to theschematic arrangement shown in FIGS. 1 and 2, between the parts of thecooling system to be vented so that the cooling medium level 28' in theexpansion tank 28, which has an automatic vent mechanism of conventionalconstruction (not shown), is disposed at all times at the geodeticallyhighest place of the cooling system.

The thermostat housing 59 illustrated in FIGS. 3 to 5 corresponds inprinciple to the thermostat housing 11 in FIGS. 1 and 2. The samereference numerals will be used for the cooling medium lines and for thevent lines as have been used in connection with FIGS. 1 and 2.

The thermostat housing 59 involves a casting which is made preferably ofaluminum or other known lightmetal alloys. It is composed externallyessentially of a housing part 60 and of ahousing cover 61. The housingcover 61 is secured at the housing part 60 by means of bolts 62. A seal63 is provided between the abutment surfaces of the housing part 60 andof the housing cover 61.

The housing part 60 includes a fastening flange with fastening eyes 64and 65 (FIG. 3) for its fastening at the engine. Additionally, theconnecting nipples 66, 67 and 68 for the cooling medium line 8 leadingfreely or unobstructedly to the radiator, for the discharge line 27 andfor the return line 23, respectively, are additionally provided at thehousing part 60.

The connecting nipple 69 is provided at the housing cover 61 for theradiator return line 16. For purposes of venting the thermostat housing59, the vent lines 38 and 39 terminate in the housing cover 61 thereofat geodetically high places. The further vent line 41 branches off fromthe vent line 39.

The flow directions of the cooling medium flowing into or out of thethermostat housing 59 are indicated by arrows 70, 71, 72 and 73.

At the height of a first separating plane 74 between the housing partand the housing cover 61 termi nates an approximately cylindricalhousing insert 75 within the thermostat housing 59; the housing insert75 encloses a combining place 76 and is supported with its end oppositethe first separating plane 74 against a fastening flange 78 of a coolingmedium valve 79. The fas tening flange 78 rests on the sealing ring 80which in its turn is embedded in a recess within the housing part 60.The housing insert 75 and the fastening flange 78 abut against oneanother in a second separating plane 81. By means of bolts 62, thehousing insert 75 is retained against the sealing ring 82 and thefastening flange 83 of the three-way thermostat 84 against the shoulder85 of a recess within the housing cover 61.

The three-way thermostat 84 and the cooling medium valve 79 are stalledinto the thermostat housing 59 coaxially aligned to one another. Theyhave essentially the same construction as can be seen from the schematicillustration in FIGS. 1 and 2. The three-way thermostat 84 includes anexpansion element 86 which is supported at the bracket-like supportmember 88 of yoke shape by way of the piston rod 87 and, beginning witha predetermined temperature, moves in the direc tion toward the coolingmedium valve 79. The disk valves 90 and 91 mounted on the expansionelement 86, which corresponds to the disk valves 18 and 19 illustratedin FIGS. 1 and 2, are thereby displaced in the same direction, on theone hand, away from the valve seat 92 and, on the other, toward thevalve seat 93. As a result thereof, the control openings 94 and 95 are,respectively, opened and closed. The movement of the expansion element86 takes place against the resistance of a compression spring 96 whichis supported, on the one hand, at a further bracket-like curved supportmember 97 which is connected to the fastening flange 83 and to thesupport member 88 and is slidingly supported on an outer surface of theexpansion element 86, and on the other, at the surface of the disk valve90 facing the curved support member 97. As a result thereof, at atemperature of the cooling medium which lies below the controltemperature of the expansion element 86, the expansion element 86 andtherewith also the disk valve 90 as also the disk valve 91 are movedback in a direction toward the support member 88. The disk valve 90thereby abuts sealingly against its valve seat 92.

The disk valve 91 is axially displaceably mounted on the tapered end ofthe expansion element 86 and is axially secured by a ring 91 In orderthat a sealing abutment of the disk valve 91 at its valve seat 93 isassured, a compression spring 98 is provided which is supported at thesurface of the disk valve 91 facing the curved support member 97 and ata collar 99 of the expansion element 86. The valve seat 93 may, asillustrated in this embodiment, be constructed in one piece with thehousing insert 75, as a part of this housing insert or at the fasteningflange 78 or at the curved bracket-like support member 100 of thecooling medium valve 79.

The construction of the cooling medium valve 79 is similar to that ofthe three-way thermostat 84. Also in this case the expansion element 101is moved in the direction away from the curved support member 100 at apredetermined temperature by means of the piston rod 102 which issupported at the curved support member 100. As a result thereof, thedisk valve 103 secured on the expansion element 101 is moved away fromthe valve seat 106 against the force of the compression spring 104 whichis supported at the bracket-like, yokeshaped support member 105 and atthe disk valve 103. The support members 100 and 105, the valve seat 106which is a part of the fastening flange and the fastening flange 78 arerigidly connected with each other.

The cooling medium valve 79 projects with its expansion element 101 intothe cooling medium line 8. Up to its control temperature, the coolingmedium valve 79 closes the control opening 107 and together with thealsoclosed disk valve 90 of the three-way thermostat 84, preventsthereby any cooling medium circulation through the by-pass 20 andthrough the radiator. With a temperature increase of the cooling mediumin the cooling medium line 8 by thermo-siphoning flow out of the engine,the cooling medium valve 79 responds, and the disk valve 103 opens upthe control aperture 107 so that the cooling medium reaches the returnline 23 through the control opening 95 in the by-pass 20'. With afurther temperature increase of the cooling medium, the three-waythermostat 84 responds, opens with its disk valve 90 the control opening94 and closes with its disk valve 91 the control opening 95. As a resultthereof, the by-pass 20' through the control opening 107 is increasinglyinterrupted and the cooling medium flows to the radiator 9 by way of thecooling medium line 8. From there, it returns into the housing cover 61by way of the radiator return line 16 and flows through the controlopening 94 in the combining place 76 and from there to the coolingmedium pump 24 by way of the return line 23.

The connecting nipples 109 and 110 contain parts of the vent lines 39and 38 for the conduction of the air to the expansion tank 28 and fromthe radiator 9. The connecting nipple 109 is illustrated in crosssection in FIG. 5 so that the float valve 111, schematically illustratedin FIGS. 1 and 2, becomes visible. The float valve 111 includes aconical valve body 112 with a cylindrical guide section 113 which arecombined into a structural member. The associated valve seat 114 isconstructed of complementary conical shape. The vent lines 39 and 41terminate in the surface of the valve seat 114. The location of thedischarge of the vent line 41 is designated by reference numeral 115.

As soon as the cooling medium level reaches the float valve 111 duringthe filling of the cooling system with cooling medium, the float valve111 is pressed against the surface of the valve seat 114. As a resultthereof, a penetration of the cooling medium into the vent line 39leaving the thermostat housing is prevented and a cooling mediumcirculation through the vent lines 38 and 39 which is possible as such,by way of the expansion tank 28, of the line 29, the discharge line 27.the thermostat housing 11, the return line 23, the cooling medium pump24, the cooling line 25, the areas 2 and 3 of the cooling jacket of theengine 1, the cooling medium line 8, the radiator 9, the radiator returnline 16 and the vent line 38 in parallel thereto back into the interiorof the housing cover 61 is avoided thereby. Also, a shortened coolingmedium circulation which in par- 9 ticular does not include theexpansion tank 28 by way of the vent line 41 is precluded.

While we have shown and described only one embodiment in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art, and we therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

We claim:

1. A circulating cooling installation for piston internal combustionengines, which comprises cooling jacket means and control means operableto limit the cooling medium circulation through the cooling jacket meansat least within the area of the combustion zones of the engine up to afirst predetermined limit value after the cold start of the engine,above the first predetermined limit value to initially confine thecirculation to a closed circulation by-passing a radiator means andavoiding a fresh water exchange, and above a further predeterminedtemperature limit value to include in the cooling medium circulation theradiator means and at least one of heat-exchanger means and fresh waterexchange, the control means including a first means and a three-waythermostat means each having a separate control element, the first meansbeing actuated after reaching the first limit value and the three-waythermostat means being actuated after reaching the further temperaturelimit value, characterized in that the control element of said firstmeans is arranged at a place at which at least approximately the highestoccurring cooling medium temperature becomes effective when the coolingmedium stands still, whereas the control element of the three-waythermostat means is disposed in the flow area of the closed circulation.

2. An installation according to claim 1, characterized in that the firstpredetermined limit value is a predetermined first temperature value ofthe engine.

3. An installation according to claim 1, characterized in that the firstpredetermined limit value is a predetermined period of time after thecold start of the engine.

4. An installation according to claim 3, characterized in that the firstpredetermined limit value is a predetermined first temperature value ofthe engine.

5. An installation according to claim 1, characterized in that the firstmeans is a cooling medium valve means.

6. An installation according to claim 1, characterized in that the firstmeans is a cooling medium pump means adapted to be shut off.

7. An installation according to claim 6, characterized in that the firstmeans is a cooling medium valve means.

8. An installation according to claim 1, characterized in that thecontrol elements are expansion elements.

9. An installation according to claim 1, characterized in that theclosed circulation includes a by-pass circulation means.

10. An installation according to claim 1, which includes a by-passmeans, and in which a cooling medium valve means forming part of thefirst means and the three-way thermostat means are combined in a commonthermostat housing means, characterized in that the cooling medium valvemeans and a disk valve means of the three-way thermostat means whichcontrols the by-pass means, respectively open and close two controlaperture means disposed in series with each other in the flow direction.

11. An installation with a line system with several cooling medium linesincluding a radiator return line and a cooling medium return line,according to claim 10, characterized in that the thermostat housingmeans includes two parts, and in that a simple-acting thermostat insertmeans is provided as cooling medium valve means and a double-actingthermostat insert means is provided as three-way thermostat means, saidsimpleacting thermostat insert means including one disk valve means andone expansion element while the doubleacting thermostat insert meansincludes two disk valve means and one expansion element, the coolingmedium valve means being arranged within the area of a branching placeof one of said cooling medium lines, at which a line section connectedwith a cooling-jacket discharge aperture means located at a geodeticallyhigh place splits up into the by-pass means and into a free coolingmedium line extending to the radiator means, in such a manner and beingsealingly clamped by means ofa fastening flange means connected with avalve seat means in a separating plane between the two housing parts insuch a manner that the expansion element of the cooling medium valvemeans protrudes into said one cooling medium line, and the three-waythermostat means being arranged within the area of a combining place ofthe cooling medium lines, in which at least the by-pass means, theradiator return line and the return line to the cooling medium pumpmeans terminate in such a manner and being sealingly clamped by means ofa fastening flange means, at which is formed a valve seat means, betweenthe two housing parts in such a manner that the expansion element of thethermostat means is located at least in part in the combining place andthe disk valve means thereof alternately control the radiator returnline and the by-pass means.

12. An installation according to claim 11, characterized in that thethermostat housing means essentially consists of a housing partcontaining essentially the branching and combining places, of anapproximately cylindrical housing insert means which is arranged insidesaid housing part between the two separating planes and which includesan end face abutment collar for the support against the fastening flangemeans of the cooling valve means and of the three-way thermostat meansas well as at least one radial aperture means for the return line to thecooling medium pump means, and of a housing cover which abuts with aflange surface in the separating plane containing the fastening flangemeans of the three-way thermostat means, against at least one of the twoparts consisting of an end face of the housing part and an abutmentcollar of the housing insert means, forms a part of the radiator returnline and receives a part of the three-way thermostat means.

13. An installation according to claim 12, characterized in that thecontrol aperture means for the disk valve means of the three-waythermostat means controlling the by-pass means is arranged at thehousing insert means.

14. An installation according to claim 13, characterized in that thecontrol elements are expansion elements.

15. An installation according to claim 11, characterized in that thecontrol aperture means for the disk valve means of the three-waythermostat means controlling the by-pass means is arranged at thehousing insert means.

1. A circulating cooling installation for piston internal combustionengines, which comprises cooling jacket means and control means operableto limit the cooling medium circulation through the cooling jacket meansat least within the area of the combustion zones of the engine up to afirst predetermined limit value after the cold start of the engine,above the first predetermined limit value to initially confine thecirculation to a closed circulation by-passing a radiator means andavoiding a fresh water exchange, and above a further predeterminedtemperature limit value to include in the cooling medium circulation theradiator means and at least one of heat-exchanger means and fresh waterexchange, the control means including a first means and a three-waythermostat means each having a separate control element, the first meansbeing actuated after reaching the first limit value and the three-waythermostat means being actuated after reaching the further temperaturelimit value, characterized in that the control element of said firstmeans is arranged at a place at which at least approximately the highestoccurring cooling medium temperature becomes effective when the coolingmedium stands still, whereas the control element of the three-waythermostat means is disposed in the flow area of the closed circulation.2. An installation according to claim 1, characterized in that the firstpredetermined limit value is a predetermined first temperature value ofthe engine.
 3. An installation according to claim 1, characterized inthat the first predetermined limit value is a predetermined period oftime after the cold start of the engine.
 4. An installation according toclaim 3, characterized in that the first predetermined limit value is apredetermined first temperature value of the engine.
 5. An installationaccording to claim 1, characterized in that the first means is a coolingmedium valve means.
 6. An installation according to claim 1,characterized in that the first means is a cooling medium pump meansadapted to be shut off.
 7. An installation according to claim 6,characterized in that the first means is a cooling medium valve means.8. An installation according to claim 1, characterized in that thecontrol elements are expansion elements.
 9. An installation according toclaim 1, characterized in that the closed circulation includes a by-passcirculation means.
 10. An installation according to claim 1, whichincludes a by-pass means, and in which a cooling medium valve meansforming part of the first means and the three-way thermostat means arecombined in a common thermostat housing means, characterized in that thecooling medium valve means and a disk valve means of the three-waythermostat means which controls the by-pass means, respectively open andclose two control aperture means disposed in series with each other inthe flow direction.
 11. An installation with a line system with severalcooling medium lines including a radiator return line and a coolingmedium return line, according to claim 10, characterized in that thethermostat housing means includes two parts, and in that a simple-actingthermostat insert means is provided as cooling medium valve means and adouble-acting thermostat insert means is provided as three-waythermostat means, said simple-acting thermostat insert means includingone disk valve means and one expansion element while the double-actingthermostat insert means includes two disk valve means and one expansionelement, the cooling medium valve means being arranged within the areaof a branching place of one of said cooling medium lines, at which aline section connected with a cooling-jacket discharge aperture meanslocated at a geodetically high place splits up into the by-pass meansand into a free cooling medium line extending to the radiator means, insuch a manner and being sealingly clamped by means of a fastening flangemeans connected with a valve seat means in a separating plane betweenthe two housing parts in such a manner that the expansion element of thecooling medium valve means protrudes into said one cooling medium line,and the three-way thermostat means being arranged within the area of acombining place of the cooling medium lines, in which at least theby-pass means, the radiator return line and the return line to thecooling medium pump means terminate in such a manner and being sealinglyclamped by means of a fastening flange means, at which is formed a valveseat means, between the two housing parts in such a manner that theexpansion element of the thermostat means is located at least in part inthe combining place and the disk valve means thereof alternately controlthe radiator return line and the by-pass means.
 12. An installationaccording to claim 11, characterized in that the thermostat housingmeans essentially consists of a housing part containing essentially thebranching and combining places, of an approximately cylindrical housinginsert means which is arrangeD inside said housing part between the twoseparating planes and which includes an end face abutment collar for thesupport against the fastening flange means of the cooling valve meansand of the three-way thermostat means as well as at least one radialaperture means for the return line to the cooling medium pump means, andof a housing cover which abuts with a flange surface in the separatingplane containing the fastening flange means of the three-way thermostatmeans, against at least one of the two parts consisting of an end faceof the housing part and an abutment collar of the housing insert means,forms a part of the radiator return line and receives a part of thethree-way thermostat means.
 13. An installation according to claim 12,characterized in that the control aperture means for the disk valvemeans of the three-way thermostat means controlling the by-pass means isarranged at the housing insert means.
 14. An installation according toclaim 13, characterized in that the control elements are expansionelements.
 15. An installation according to claim 11, characterized inthat the control aperture means for the disk valve means of thethree-way thermostat means controlling the by-pass means is arranged atthe housing insert means.